Thermostat for refrigerating apparatus



1965 SHIGEO MAMIYA ETAL 3,169,404

THERMOSTAT FOR REFRIGERATING APPARATUS United States Patent 3,169,404 THERMOSTAT FGR REFMGERA'HNG APPARATUS Shigeo Mnmiya and Takeshi Gdashima, both of Tokyo,

Japan, assignors to Saginomiya Seisakusho Co., Ltd,

Tokyo, Japan Fiied Sept. 7, 1961, Ser. No. 136,655 Claims priority, appiication Japan, Sept. 16, 1960, {utiiity model) 35/ 16,713 2 Claims. (Ci. 74-2) The present invention relates to a thermostat to be utilized in electrical refrigerating equipment such as an electrical refrigerator or the like.

It is an object of the present invention to provide a thermostat by which when frost occurs for one reason or another on the cooling pipe of a refrigerator while the refrigeration is going on, the cooling operation is stopped and the cooling pipe is defrosted by means of hot gas circulated in said cooling pipe or other heating means by pressiru a push button and, as soon as the frost is removed, the refrigerator is again automatically (or manually if so desired) set in operation again through the action of a sensitive tube.

Another object of the present invention is to provide a thermostat in which there is provided a push button for stopping refrigeration and another push button for resuming refrigeration. Both push but-tons can be operated manually and are situated side by side.

With these and other objects in view, as hereinafter appearing, an embodiment of the present invention is fully described in the ensuing specification and delineated in the claims appended hereto.

In the attached drawing showing an embodiment of the present invention:

FIG. 1 is a plan view of a thermostat according to the present invention;

FIG. 2 is a front view of a longitudinal section of the same;

FIG. 3 is the same of a cross section showing the operating condition thereof; and

FIG. 4 is a front view thereof partly sectioned.

Now explaining an embodiment of the present invention with reference to the attached drawing.

1 is a casing. 2 is a diaphragm. 3 is a connecting tube connected with the diaphragm 2 and leading to a sensitive tube. 4 is a microswitch. 5 is an activating plate mounted for rotative movement on an axle 6 the lower part of said activating plate 5 being connected to the diaphragm 2 by means of a pivot 7. On the upper part of the activating plate 5 there is formed a bent portion 9 having a cut-out portion 8. 16 is a leaf spring which is in contact with an activating projection 11 of a microswitch 4. 12 and 13 are push buttons. On the lower part of the push button 12 there is provided a trip plate 14, one end of which is movably attached to the casing 1. On the lower part of the trip plate 14 the leaf spring 14) is afiixed. 15 is a coil spring stretched between a holder 14', attached to said trip plate 14 by means of an adjusting screw 16, and a bent piece 5 of said activating plate 5 and to said holder 14. Adjusting screw 16 for adjusting the tension of the coil spring 15 is screwed in. The tip 14" of the trip plate 14 is detachably fitted to the cut-out portion 8 of said bent plate 9. At the lower part of the push button 13 a rotating piece 17 is rotatably attached to the casing 1 ice by means of a claw 17' thereof; and, a projection 18 thereof is set in contact with the bent portion 9.

Now explaining the operation of the present invention, when the push button 12 is pressed, the activating projection 11 is also pressed downward through the trip plate 14. The leaf-spring 1t) and the microswitch 4 are activated and, simultaneously, the tip-14" of the trip plate 14 is made to fit into the cut-out portion 8 of the bent plate 9 to hold the activating projection 11 of the microswitch 4 in the depressed condition. Thereby, in an electric refrigerator, for an example, warm gas is circulated through the cooling pipe and the defrosting operation is carried out. As the temperature in the refrigerator rises, the diaphragm 2 is made to expand by the action of the heat sensitive element in the sensitive tube and the activating plate 5 is made to rotate counter-clockwise about the axle 6 (as shown in FIG. 3) and the tip 14" of the trip plate 14 is disengaged from the cut-out portion 8 of the bent plate 9 whereby the trip plate 14 is raised by the force of the coil spring 15 and the activating projection 11 is restored to its original position and the cooling operation is resumed.

If it is desired to start the cooling operation independently from the operation of the heat sensitive tube, the push button 13 may be manually pressed to rotate the rotating piece 17 around the claw 17 and making the activating plate 5 rotate countenclockwise around the axle 6 as shown in FIG. 3; the bent plate 9 being pressed by the projecting piece 18. Thus, the tip 14" of the trip plate 14 is disengaged from the cut-out portion 8 of the bent plate 9 and the push button 12 is pushed upward by means of the spring 15. The pressure applied to the activating projection 11 of the microswitch 4 is released. Thereby, the cooling operation is resumed.

As the present invention is constructed as described above, whenever frost occurs on the cooling pipe, by pressing the push button, the cooling operation is stopped and the frost is removed and the cooling operation can automatically be resumed. Furthermore, wherein it is desired to resume the cooling operation, for an example, when the button is pressed by mistake, the cooling can be resumed independently from the operation of the sensitive tube by pressing the other button.

Although the invention has been described hereinbefore by reference to a specific embodiment, it is to be understood that this embodiment may be modified in many ways within the scope of the invention as defined in the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

I. In combination, a first push button; trip plate means having a tip portion and including an integrally connected leaf spring member, said trip plate means and leaf spring member being depressable in response to depression of said first push button; a diaphragm including a temperature sensing means connected therewith for expanding said diaphragm in response to a predetermined temperature sensed by said sensing means; activating means including a base portion bearing against said diaphragm, said activating means being pivoted whereby expansible motion of said diaphragm causes limited pivotal movement of said activating means, said activating means including a cut-out portion at an end thereof opposite said base portion, said tip portion of said trip plate means being moved into said cut-out portion for latching engagement of said activating means with said trip plate means in response to depression leaf spring are latched in the depressed condition; spring means connected between said activating means and said h trip plate means for maintaining said tip portion of said trip plate means in said cut-out portion for latching engagement, the expansion of said diaphragm in response to said temperature sensing means acting'against said spring means to unlatch said trip plate and activating means; a second push button; and, a second linkage means including a tip portion movable in response to the depression of said second push button to actively engage said activating means for urging said activating means out of latching engagement with said trip plate means.

w 2. The combinations according to claim 1, wherein there is included in said' diaphragmisurface a depression, and wherein said base portion of said activating means infcludes a fulcrtlm portion receivable by the depression; said expansible motion of said diaphragm'being transmitted to said activating means through said fulcrum portion.

References fitted in theiile of this patent UNITED STATES PATENTS Bast 2- Mar. 27, 19: 4 2,671,838 Senn Mar. 9, 1954 r 2,717,494 Doeg Sept. 13, 1955, 2,897,327 DeS-midt et a1. July 28, 1959 2,918,804 Iglehart Dec. 279, 1959 FOREIGN PATENTS 548,557 Canada Nov. 5, 1957 l 1,142,199 Germany Q Ian. 10, 1963 

1. IN COMBINATION, A FIRST PUSH BUTTON; TRIP PLATE MEANS HAVING A TIP PORTION AND INCLUDING AN INTEGRALLY CONNECTED LEAF SPRING MEMBER, SAID TRIP PLATE MEANS AND LEAF SPRING MEMBER BEING DEPRESSABLE IN RESPONSE TO DEPRESSION OF SAID FIRST PUSH BUTTON; A DIAPHRAGM INCLUDING A TEMPERATURE SENSING MEANS CONNECTED THEREWITH FOR EXPANDING SAID DIAPHRAGM IN RESPONSE TO A PREDETEMINED TEMPERATURE SENSED BY SAID SENSING MEANS; ACTIVATING MEANS INCLUDING A BASE PORTION BEARING AGAINST SAID DIAPHRAGM, SAID ACTIVATING MEANS BEING PIVOTED WHEREBY EXPANSIBLE MOTION OF SAID DISPHRAGM CAUSES LIMITED PIVOTAL MOVEMENT OF SAID ACTIVATING MEANS, SAID ACTIVATING MEANS INCLUDING A CUT-OUT PORTION AT AN END THEREOF OPPOSITE SAID BASE PORTION, SAID TIP PORTION OF SAID TRIP PLATE MEANS BEING MOVED INTO SAID CUT-OUT PORTION FOR LATCHING ENGAGEMENT OF SAID ACTIVATING MEANS WITH SAID TRIP PLATE MEANS IN RESPONSE TO DEPRESSION OF SAID FIRST PUSH BUTTON WHEREBY SAID TRIP PLATE MEANS AND LEAF SPRING ARE LATCHED IN THE DEPRESSED CONDITION; SPRING MEANS CONNECTED BETWEEN SAID ACTIVATING MEANS AND SAID TRIP PLATE MEANS FOR MAINTAINING SAID TRIP PORTION OF SAID TRIP PLATE MEANS IN SAID CUT-OUT PORTION FOR LATCHING ENGAGEMENT. THE EXPANSION OF SAID DIAPHRAGM IN RESPONSE TO SAID TEMPERATURE SENSING MEANS ACTING AGAINST SAID SPRING MEANS TO UNLATCH SAID TRIP PLATE AND ACTIVATING MEANS; A SECOND PUSH BUTTON; AND, A SECOND LINKAGE MEANS INCLUDING A TIP PORTION MOVABLE IN RESPONSE TO THE DEPRESSION OF SAID SECOND PUSH BUTTON TO ACTIVELY ENGAGE SAID ACTIVATING MEANS FOR URGING SAID ACTIVATING MEANS OUT OF LATCHING ENGAGEMENT WITH SAID TRIP PLATE MEANS. 